High-voltage mercury-arc rectifier



Oat. 1, 1968 BUTAEV ETAL HIGH VOLTAGE MERCURY-ARC RECTIFIER Filed Aug. 5, 1965 l/VSUL/ITM m m m w w United States Patent HIGH-VOLTAGE MERCURY-ARC RECTIFIER Filipp Ivanovich Butaev, Krasnokazarmennaya ulitsa 19,

kv. 43, Nikolai Semenovich Klimov, Krasnokazarmennaya ulitsa 19, kv. 94, Alexei Alexandrovich Pertsev,

Krasnokazarmennaya ulitsa 19, kv. 136, Nikolai Pavlovich Stepauov, Sadovo-Sukharevskaya ulitsa 2/ 34,

kv. 6, Alexandr Mikhailovich Shemaev, Metrostroevskaya ulitsa 9, kv. 3, and Ilya Dmitrievich Shkolin,

B. Spasskaya ulitsa 7, kv. 15, all of Moscow, U.S.S.R.

Filed Aug. 3, 1965, Ser. No. 476,841 2 Claims. (Cl. 31333) ABSTRACT OF THE DISCLOSURE A high-voltage mercury arc rectifier having a grid in the form of a disc with cuts radiating from the center towards the edge, the grid being located between intermediate electrodes and an anode on one side of the grid, and a cathode and excitation anode on the other side, the latter being surrounded by a screen which covers the end portion of the excitation anode while only partially covering the cylindrical portion thereof.

The present invention relates to a high-voltage mercuryarc rectifier, and more particularly, to the design of the low-voltage unit of a high-power high-voltage mercury-arc rectifier.

There are known high-voltage mercury-arc rectifiers comprising a housing, an anode chamber, main anode insulator, an anode, a cathode, intermediate electrodes, a cooler, a voltage divider, an evacuation system, and a low-voltage unit comprising grids, a filter and excitation anodes with anode shields.

The designs of the above-mentioned mercury-arc rectifiers provide for a power not exceeding 3.3 mw. per anode.

As is known, with a load increase, the electrode temperature of the grid unit rises, thereby causing the deformation of the electrodes and failure of the rectifier, whereas an increase of the ionic flow towards the excitation electrodes (up to dozens of amperes) facilitates their intensive sputtering.

Additionally, when mercury condensate appears on or above the level of hot parts of the low-voltage unit, mercury droplets fall onto hot surfaces of the above-mentioned unit, thus bringing about a sharp increase of mercury vapor density in the rectifier, causing a failure thereof.

The primary object of the invention is to provide a high-voltage mercury-arc rectifier which serves to increase the power and reliability, to avoid possible appearance of the mercury vapor condensate and an increase in the density of mercury vapor within the zone of the electrode terminals of the low-voltage unit, as Well as to reduce the sputtering of the excitation anodes.

According to the invention, said object is attained by making the grids of the high-voltage mercury-arc rectifier in the form of discs with several through cuts, which preferably radiate from the center along a diameter and do not reach the grid edges, thus avoiding deformation of the grids.

Moreover, to eliminate a possible appearance of mercury condensate and to increase the density of mercury vapors within the electrode terminals zone of the lowvoltage unit, said terminals are separated from the rectifier housing by a cylindrical screen, whereas to reduce the sputtering of the excitation anodes their screen is made with a possibility of complete covering of the whole end portion of the excitation anodes and partial covering of their cylindrical portion.

The invention will further be described in connection with an exemplary embodiment thereof, referencebeing made to the appended drawings, wherein:

FIG. 1 is a schematic view in section of the high-voltag rectifier according to the invention;

FIG. 2 is a plan view of a grid;

FIG. 3 is a partial section view with a screen.

The high-voltage rectifier consists of housing 1 (FIG. 1), anode chamber 2, main anode insulator 3, anode 4, cathode 5, cathode cap 6 which is cooled, cooler 7, intermediate electrodes 8 with cylinders 9, grid 10, filter screen 11, excitation anodes 12, voltage divider 13 and evacuation system 14 with high-vacuum cock 15.

Referring to FIG. 1, anode chamber 2 is fixed on the upper flange of housing 1 and is provided with cooling ribs 16. Main anode insulator 3 is mounted on the upper plate of anode chamber 2. Terminals 17 of excitation anodes 12 as well as other terminals of the low voltage unit are passed through the lower plate of anode chamber (not shown in FIG. 1).

To maintain a vapor-dynamic mode of the rectifier, housing 1 is provided with channels 18 designed for the flow of coolant. Cathode cap 6 is provided with double Walls, between which coolant is circulating. Intermediate electrodes 8 are located in the lower part of cylinders 9 fixed on base insulators 19. Voltage divider 13 is connected with cylinders 9 of intermediate electrodes 8 by terminals 20 secured on anode insulator 3.

As mentioned above, the activation of a cold rectifier to a full load current may cause warping (deformation) of the grids due to uneven heating.

To avoid the above-mentioned effect, grid 10 is formed as a disc with radially directed cuts 21 (FIG. 2) which do not reach the grid edge.

To prevent the failures in operation caused by condensation of the mercury vapor within the tube to produce droplets falling onto hot surfaces of the low-voltage unit (composed of the grid 10, filter 11, and excitation anodes 12) and resulting in an intolerable increase of mercury vapor density, the hot parts of the low-voltage unit are separated from the cold walls of housing 1 (FIG. 1) by a cylindrical screen 22, thus eliminating the possibility of the appearance of condensate in the electrode terminals zone of said unit and cone 23 (serving to concentrate vapor and electron flow to the anode).

To reduce sputtering of excitation anodes 12, screen 24 (FIG. 3) is made so as to completely cover the end part of the excitation anodes, the side surface of said screen being provided with a cut due to which the cylindrical portion of the anodes is closed only partially for its greater length.

The described grid unit of the high-voltage mercury-arc rectifier provides for more current power per anode-up to 7.5 mw.

What is claimed is:

1. A high-voltage mercury-arc rectifier comprising a housing provided with channels for coolant; a cooled cathode cap located inside said housing; an anode chamber mounted on said housing; a main anode insulator fixed on said anode chamber; a cathode located in the bottom of said housing; a hollow anode located inside said anode chamber and said main anode insulator; an anode cooler located inside said anode; intermediate electrodes in said anode chamber; a voltage divider connected with said intermediate electrodes; a filter with a cone located inside said housing; a grid having several through cuts extending from the center thereof without reaching the perimeter of the grid, said grid being located between said intermediate electrodes and said filter; excitation anodes with a screen, the latter said anodes being located inside said housing; an evacuation system mounted of an excitation anode on said housing; and a screen located inside said housing for separating the walls thereof from the excitation anodes and the filter and cone to avoid the generation of condensate within the zone of the terminals of the excitation anodes.

2. A high-voltage mercury-arc rectifier comprising a housing provided with channels for coolant; a cooled catho'de cap located inside said housing; an anode chamber mounted on said housing; a main anode insulator fixed on said anode chamber; a cathode located in the bottom of housing; a hollow anode located inside said anode chamber and said main anode insulator; an anode cooler located inside said anode; intermediate electrodes located in said anode chamber; a voltage divider connected with said intermediate electrodes; a filter with a cone located inside said housing; a grid having several through cuts extending from the center thereof without reaching the grid edge, said grids being located between said inter; mediate electrodes and said filter; an evacuation system mounted on said housing; and excitation anodes with a screen, said excitation anodes being located inside said housing, said screen completely covering the end part of said excitation anodes and partially covering the cylindrical portion thereof. 1

References Cited UNITED STATES PATENTS 2,610,305 9/1952 Watrous 313-148 2,797,348 6/ 1957 Watrous 313-348 DAVID J. GALVIN, Primary Examiner. 

